The conversion of alcohols to hydrocarbons is generally not commercially feasible. In fact, the majority of commercial alcohols are produced from hydrocarbons. Alcohol-to-hydrocarbon conversion is further prohibitive due to the significant cost requirements of current conversion processes. Hence, alcohol obtained by natural means (e.g., by fermentation of biomass) would be a significantly more cost-efficient feedstock.
However, a major obstacle in applying current conversion methodology to biomass-produced alcohols (i.e., bio-alcohols) is the high concentration of water (and concomitant low alcohol concentrations) typically encountered in fermentation streams produced in biomass-to-alcohol refineries. Current alcohol-to-hydrocarbon conversion processes are generally incapable or highly ineffective in providing such conversion at such dilute alcohol and high water concentrations. Instead, current alcohol-to-hydrocarbon conversion processes generally require pure alcohol (i.e., in the substantial absence of water). Moreover, concentration and/or distillation of alcohol from a fermentation stream to accommodate current technologies would be highly energy intensive, and thus, would largely offset gains made in the initial low cost of using a bio-alcohol.